Rheumatoid Arthritis vs. Osteoarthritis

  • Medical Author:
    William C. Shiel Jr., MD, FACP, FACR

    Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

  • Medical Editor: Catherine Burt Driver, MD
    Catherine Burt Driver, MD

    Catherine Burt Driver, MD

    Catherine Burt Driver, MD, is board certified in internal medicine and rheumatology by the American Board of Internal Medicine. Dr. Driver is a member of the American College of Rheumatology. She currently is in active practice in the field of rheumatology in Mission Viejo, Calif., where she is a partner in Mission Internal Medical Group.

What is the difference between rheumatoid arthritis and osteoarthritis?

While both rheumatoid arthritis and osteoarthritis can lead to significant joint destruction and functional disability, there are many basic differences between these two forms of arthritis.

Rheumatoid arthritis

  • Rheumatoid arthritis is a destructive autoimmune joint disease that features inflammation in the joint lining tissue (synovium) that normally produces lubrication and nutrient fluid for joints. When this tissue remains inflamed, it leads to deformity (by loosening joint ligaments) and to joint destruction (by eroding away cartilage and bone).
  • Rheumatoid arthritis is an autoimmune disease characterized by an overactive, misdirected immune system.
  • In rheumatoid arthritis, the misdirected immune system attacks the joint lining tissue leading to destructive inflammation of the joints. Ligaments, cartilage, and bone can all be damaged from rheumatoid arthritis.
  • Rheumatoid arthritis is also a systemic disease, meaning that it can additionally involve tissues throughout the body, including the lungs, skin, and eyes.
  • Rheumatoid arthritis tends to affect many joints symmetrically on both sides of the body.
  • The inflammation of active rheumatoid arthritis is characterized by joint stiffness in the morning lasting over 30 minutes.


  • Osteoarthritis is a disease of the cartilage of joints.
  • Osteoarthritis is not a systemic disease and not an autoimmune disease.
  • Osteoarthritis is partly a result of natural aging of the joint. With aging, the water content of the cartilage increases, and the protein makeup of cartilage degenerates as a function of biologic processes. Eventually, cartilage begins to degenerate by flaking or forming tiny crevasses.
  • In advanced osteoarthritis, there is a total loss of the cartilage cushion between the bones of the joints.
  • Repetitive use of the worn joints over the years can mechanically irritate and inflame the cartilage, causing joint pain and swelling.
  • Loss of the cartilage cushion causes friction between the bones, leading to pain and limitation of joint mobility.
  • Inflammation of the cartilage can also stimulate new bone outgrowths (spurs, also referred to as osteophytes) to form around the joints.
  • Osteoarthritis occasionally can develop in multiple members of the same family, implying a hereditary (genetic) basis for this condition.
  • Osteoarthritis is, therefore, felt to be a result of a combination of each of the above factors that ultimately lead to a narrowing of the cartilage in the affected joint.
  • Osteoarthritis is sometimes referred to as degenerative joint disease.

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Firestein, Gary S., et al. Kelley's Textbook of Rheumatology, Edition 9. China: Elsevier Health Sciences, 2012.